Windows Server 2012 Lab - Part 7 - DHCP Installation 1

Before we get into WDS tutorial I would like to briefly cover DHCP server role and installation in Windows Server 2012, as we will need to have a DHCP server in place for IP assignments in WDS. (Will discuss in future tutorials).

I will write down few articles on DHCP administration and configuration in future tutorials. For now I will just touch base an overview about DHCP, server role installation, and creating scope for our lab for new clients.

What is DHCP?
Dynamic Host Configuration Protocol!!!! Yay!
Whenever anyone asks me about DHCP, all I used to tell 'em that. But hey, I wondered how many out there actually or literally do visualize in their mind about DHCP.

Here is what I think. OR an example scenario.

There is a school (DOMAIN).

In that school there is a class (NETWORK SEGMENT).

For that class there is a class teacher (dedicated DHCP server).

And that class (NETWORK SEGMENT) has 10 students (CLIENTS or PCs or Devices for example).

In this scenario, teacher will handout unique roll number IDs to students in the class.
For example, John is 1, Bagga is 2, Ronaldo is 3, Rose is 4, Nigel is 5 etc.,

One day there is a new student to the class and he needs a new ID. Now the teacher cannot handout existing roll numbers 1 to 5 as they are in use. And in case if the teacher hands out existing roll number to new student, they would clash while attending their presence in the room. And if teacher calls any student by roll number, since there existing a duplicate ID, two students will answer his call at the same time leading to confusion and clash.

And more importantly in the teacher hands out the roll numbers to students on a lease basis (a term or semister in this case). After the lease the roll numbers will change and some students may get the same roll number (chances are there).

Now lets get into the technical terms:

In the above example, teacher (DHCP server) hands out IP addresses to new students (Clients, PCs etc.,) based on a lease period (default is 8 days in Windows DHCP).

Now if you have a new client PC installed (new student), our DHCP server (teacher) will assign a new IP address (roll number) from the address pool.

If any PC has an assigned or static IP address of already in user IP then DHCP will clash records.
E.g: same roll number for multiple students.

If I put in more technical words,
Source: an excellent article at Wikipedia.org
The Dynamic Host Configuration Protocol (DHCP) is a standardized network protocol used on Internet Protocol (IP) networks for dynamically distributing network configuration parameters, such as IP addresses for interfaces and services. With DHCP, computers request IP addresses and networking parameters automatically from a DHCP server, reducing the need for a network administrator or a user to configure these settings manually.

DHCP assigns an IP address when a system is started, for example:

1. A user turns on a computer with a DHCP client.
2. The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer.
3. The router directs the DISCOVER packet to the correct DHCP server.
4. The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address (if any) to give to the client. The server then temporarily reserves that address for the client and sends back to the client an OFFER (or DHCPOFFER) packet, with that address information. The server also configures the client's DNS servers, WINS servers, NTP servers, and sometimes other services as well.
5. The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address.
6. The server sends an ACK (or DHCPACK) packet, confirming that the client has a been given a lease on the address for a server-specified period of time.

When a computer uses a static IP address, it means that the computer is manually configured to use a specific IP address. One problem with static assignment, which can result from user error or inattention to detail, occurs when two computers are configured with the same IP address. This creates a conflict that results in loss of service. Using DHCP to dynamically assign IP addresses minimizes these conflicts.

I believe that you got an idea of DHCP